Liquid-based fine needle aspiration biopsy of papillary thyroid carcinoma: Logistic regression analysis with conventional and new cytomorphologic features

Abstract

OBJECTIVE: The morphological interpretation of liquid-based preparation (LBP) remains a diagnostic challenge due to altered cytomorphology with technical reason. Only a few published accounts of the cytopathological features needed for diagnosis of papillary thyroid carcinoma (PTC) on an LBP exist. We utilized the SurePath LBP system to evaluate conventional and newly recognized cytomorphologic features on histologically confirmed PTC to identify their potent diagnostic significance compared to benign follicular neoplasm (BFN). STUDY DESIGN: One-hundred and three cases of PTC and 84 BFNs were collected using preoperative fine needle aspiration biopsies. We evaluated and compared 16 cytomorphologic findings in PTC and BFN using an LBP. RESULTS: Among the conventional criteria, papillary structures, fewer background colloids and macrophages, hobnail patterns (54.4% in PTC vs. 10.7% in BFN; p < 0.001) and swirling architecture (14.6% in PTC vs. 0% in BFN; p < 0.001; positive predictive value 100.0%) were significant diagnostic findings for PTC compared to BFN. The hobnail pattern was shown as a newly recognized strong diagnostic parameter for PTC (odds ratio 50.157, p < 0.001). CONCLUSION: The identified distinctive cytological criteria may be helpful in cases where conventional criteria for PTC are insufficient. Furthermore, application of these findings, along with classical criteria, may enhance the diagnostic accuracy of PTC by fine needle aspiration biopsy.